ox: Fix "Symbol's value as variable is void: org-export--default-title"

* lisp/ox.el (org-export--default-title): Fix "Symbol's value as
  variable is void: org-export--default-title".

Bug was introduced in b70e77343aa3daee9312c81c96ef5da217d7fda5.
Merge branch 'maint'
Babel: complete fix for priority order of header arguments from e79e8943de

* lisp/ob-core.el (org-babel-parse-inline-src-block-match),
  lisp/ob-exp.el (org-babel-exp-src-block): Give header arguments from
  properties priority over default header arguments.

The previous commit e79e8943de did fix this only in
ob-core.el (org-babel-parse-src-block-match).  It was already correct
in ob-lob.el (org-babel-lob-execute).
org-id: autoload `org-id-update-id-locations'

* lisp/org-id.el (org-id-update-id-locations): Autoload interactive
  function.
ob-octave: Emacs 24.4 will ditch octave-inf in favor for octave

* lisp/ob-octave.el (org-babel-octave-initiate-session): If octave-inf
  can't be loaded, try octave instead before giving up.  Emacs 24.3.50
  and upwards replaces octave-inf with just plain octave.
Makefile: add perl to babel languages for testing

* mk/default.mk (BTEST_OB_LANGUAGES): Add perl to Babel languages that
  should be tested by default.
ox: Small fix to cell width caching mechanism

* lisp/ox.el (org-export-table-cell-width): Be sure to use cache even
  when stored value is nil.
Merge branch 'maint'
Updated author list of ox-koma-letter.el

* ox-koma-letter.el: added Viktor Rosenfeld and Rasmus as
contributors to ox-koma-letters.el.

TINYCHANGE

Signed-off-by: Alan Schmitt <alan.schmitt@polytechnique.org>
ox-latex.el: Support for pgf files

* ox-latex.el (org-latex--inline-image): pgf is recognized as an
inline image and treated the same way tikz files.

Python matplotlib and pgfprint for Octave generates pgf plots
rather than TiKZ plots.  They need just be included via \input{.}.

TINYCHANGE
org-clock.el (org-clock-modify-effort-estimate): Clarify docstring

* org-clock.el (org-clock-modify-effort-estimate): Clarify
docstring.

Thanks to Ken Mankoff for raising this.
Fix previous commit
Merge branch 'maint'
Changed =#+SENDER= to =#+AUTHOR= and removed duplicated email and author variables in =ox-koma-letter.el=.

* ox-koma-letter.el: changed the unorthodox =SENDER= keyword to
  the ordinary =AUTHOR= keyword.
* ox-koma-letter.el: changed email to work as in standard
  latex exporter and dropped dedicated ox-koma-letter variable.

Signed-off-by: Alan Schmitt <alan.schmitt@polytechnique.org>
export inline svg images with htmlize
respect org-html-table-caption-above